The English TH Sound for Spanish Speakers: A Practical Guide

Two sounds, one spelling

English uses the letters TH for two different sounds. The first is voiceless: air passes between your tongue and teeth with no vibration in your throat, as in think, three, month and bath. The second is voiced: the same tongue position, but your vocal cords vibrate, as in this, the, mother and breathe. Put your fingers on your throat and say "ssss" and then "zzzz". The difference you feel is the same difference between the TH in thin and the TH in then.

Spelling will not tell you which one to use, but there is a useful pattern. Small, very frequent grammar words (the, this, that, they, them, there, then, though) almost always use the voiced sound. Content words such as think, thank, theory, health and math usually use the voiceless one.

Why Spanish speakers substitute other sounds

In most of Latin America, Spanish has no sound made with the tongue between the teeth, so the brain replaces TH with the closest familiar option: T, D or S. Speakers from much of Spain have an advantage, because the Castilian pronunciation of z and c in words like zapato or cena is very close to the voiceless TH in think. If you use that sound, you already own half of the problem.

The voiced TH has a hidden connection too. The Spanish d between vowels, as in nada or todo, is softer than the d at the start of a word. In many speakers it is already close to the English sound in other. The task is to use that soft sound deliberately, at the start of words, where Spanish would use a hard d.

The most common substitutions

• Voiceless TH replaced by T: three becomes "tree", thank becomes "tank".
• Voiceless TH replaced by S: think becomes "sink", thick becomes "sick".
• Voiced TH replaced by D: this becomes "dis", they becomes "day".
• TH at the end of a word dropped or turned into T: month sounds like "mont", with like "wit".

Some of these swaps create a different real word, which is why listeners sometimes misunderstand you. "I sink so" is usually understood from context. "We need tree tickets" can be confusing at a counter.

How to make the sound, step by step

1. Relax your jaw and let your mouth open slightly.
2. Place the tip of your tongue lightly between your upper and lower front teeth, or just touching the back of the upper teeth. Do not bite it.
3. Blow air gently over the tongue. You should hear a soft, continuous hiss. That is the voiceless TH.
4. Keep the same position and add voice from your throat. The hiss becomes a buzz. That is the voiced TH.
5. Pull the tongue back quickly into the next vowel. Native speakers do not hold the tongue out for long.

Use a mirror for the first few days. If you cannot see a small bit of tongue on TH, you are probably making a T, D or S.

A five-minute daily drill

Short, regular practice beats a single long session, a principle explained in our guide to learning a language every day without burning out. Try this routine once a day:

1. One minute of isolated sound: ten slow voiceless hisses, ten voiced buzzes, feeling your throat each time.
2. One minute of minimal pairs, said slowly and then faster: tree and three, tank and thank, sink and think, day and they, dare and there.
3. One minute of frequent words: the, this, that, think, thanks, three, with, both, other, together.
4. One minute of short phrases: "Thanks for that." "I think they're there." "Both of them." "The third Thursday of the month."
5. One minute of recording yourself saying one real sentence you need this week, then listening back for every TH.

Dictation is a useful partner to this drill. Writing down what you hear forces you to notice whether a speaker said three or tree, and that listening attention transfers to your own speech. Vocalyra's vocabulary, dictation and conjugation practice shows how these exercises fit together.

Connected speech: where TH gets harder

Many learners can say think perfectly in isolation and then lose it in a full sentence. The trickiest spots are TH next to another consonant (months, clothes, fifth) and the very frequent word the in fast speech. Two practical points help here.

• In clusters, simplify the timing, not the sound. Say "mon-ths" slowly several times before speeding up, rather than skipping the TH.
• After words ending in N, T or D, native speakers often move the tongue straight into TH without separating the sounds. "In the" and "at the" become smooth, linked movements. Practise them as single units.

How perfect does it need to be?

Many fluent English speakers around the world use T, D or F instead of TH and are perfectly understood. Your goal is clarity, not an imitation of one accent. Focus first on the cases that change meaning (three and tree, think and sink, thank and tank) and on the words you use most often. If those are clear, small imperfections elsewhere rarely matter. Exams such as IELTS also assess intelligibility rather than a specific native accent, as explained on our English exam preparation page.

Next step

Pronunciation improves fastest when it is practised alongside the vocabulary and structures at your level. If you are learning English with Spanish as your strongest language, learning English online with Vocalyra lets you work through a CEFR path with explanations in Spanish. Not sure where to start? The free placement assessment gives you a CEFR starting point before you choose a plan.